N-bromobutanimide → 1-Bromo-4-chloro-7,8-dimethylimidazo[1,2-A]quinoxaline

HRID 1025480Notes

Reaction equation

HRID 1025480 reaction equation
[Cl:1][C:2]1[C:3]2[N:4]([CH:14]=[CH:15][N:16]=2)[C:5]2[C:10]([N:11]=1)=[CH:9][C:8]([CH3:12])=[C:7]([CH3:13])[CH:6]=2.C1C(=O)N([Br:24])C(=O)C1>C1COCC1.CN1C(=O)CCC1>[Br:24][C:14]1[N:4]2[C:5]3[C:10]([N:11]=[C:2]([Cl:1])[C:3]2=[N:16][CH:15]=1)=[CH:9][C:8]([CH3:12])=[C:7]([CH3:13])[CH:6]=3

Participants

4

Reactant 2

HCID 67184N-bromobutanimide2×HCID 866653244-Chloro-7,8-dimethyl-imidazo[1,2-a]quinoxaline

Product 1

HCID 717416381-Bromo-4-chloro-7,8-dimethylimidazo[1,2-A]quinoxalineYield 81.1%

Reagents, catalysts & solvents 1

HCID 22156051tetrahydrofuran N-methylpyrrolidinoneSolvent

Procedure

To a stirred suspension of 4-chloro-7,8-dimethyl-imidazo[1,2-a]quinoxaline (32.2 g, 0.148 mot) in THF/NMP 2:1 (312 mL) was added NBS (26.3 g, 0.148 mot) in one portion at room temperature. After stirred for 18 h, additional NBS (13.1 g, 0.074 mot) was added and the mixture was stirred for additional 2 h at room temperature. After removal of the THF portion of the organic phase by vacuum evaporation, water was added (520 mL). The precipitate was filtered and the residue was washed with water, diethyl ether and dried to give 35 g of the title compound. 1H-NMR (300 MHz, d6-DMSO): δ=8.54 (1H, s), 7.75 (1H, s), 7.40 (1H, s), 2.20 (6H, s) ppm.

Workup

  1. stirringthe mixture was stirred for additional 2 h at room temperature
  2. customAfter removal of the THF portion of the organic phase
  3. customby vacuum evaporation, water
  4. additionwas added (520 mL)
  5. filtrationThe precipitate was filtered
  6. washthe residue was washed with water, diethyl ether
  7. customdried

Sources & evidence

ORD record
ord-0ebe3b7a866c4e49a7651e9a05e4bdce
Source dataset
uspto-grants-2014_05
Patent number
US08729082B2

Reaction notes

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